Search Results

This paper presents results of a coupling of the Volume-of-Fluid Large-Eddy simulation (VOF-LES) of the jet primary breakup with a Lagrangian stochastic spray simulation of a GDi multi-hole injector. The objective is to assess the potential of replacing the phenomenological models of jet primary atomization with the stochastic parcel size - velocity data extracted from the VOF-LES analysis. The paper describes the methodology and assesses the predictive capability achieved, through comparison of the Lagrangian far-field spray simulation results with the complete experimental spray characterization data under the atmospheric ambient conditions. The injector sac-nozzle flow and jet primary breakup simulation is performed with the Open-FOAM code. The simulation of the spray development processes - of propagation, evaporation and secondary atomization - is performed with the AVL-FIRE commercial CFD code adopting the standard Lagrangian discrete droplet method.

The paper presents a model-based approach to testing embedded automotive software systems in a real-time. Model-based testing approach relates to a process of creating test artifacts using various kinds of models. Real-time testing involves the use of a real-time environment to implement test application. Engineers shall use real-time testing techniques to achieve greater reliability and/or determinism in a test system. The paper contains an instruction how to achieve these objectives by proper definition, implementation, execution, and evaluation of test cases. The test cases are defined and implemented in a modeling environment. The execution and evaluation of test results is made in a real-time machine. The paper is concluded with results obtained from the initial deployment of the approach on a large scale in production stream projects.

In this paper, we present a real-time 360 degree surround system with parking aid feature, which is a very convenient parking and blind spot aid system. In the proposed system, there are four fisheye cameras mounted around a vehicle to cover the whole surrounding area. After correcting the distortion of four fisheye images and registering all images on a planar surface, a flexible stitching method was developed to smooth the seam of adjacent images away to generate a high-quality result. In the post-process step, a unique brightness balance algorithm was proposed to compensate the exposure difference as the images are not captured with the same exposure condition. In addition, a unique parking guidance feature is applied on the surround view scene by utilizing steering wheel angle information as well as vehicle speed information.

In the sensitive automotive applications like the safety restraint systems (SRS), twisted lines can be used to link the components of the system because of their property of reduction of the electromagnetic interference (EMI) coupling. Compared to the parallel lines, the twisted lines present the drawback to consume more copper in their manufacturing due to the greater length of their conductors. A parametric study based on the numerical modeling and the measurement of twisted lines is conducted in order to analyze the effect of the twisting pitch and of the untwisted part of these lines on the level of EMI coupling. This study will enable to optimize these two parameters in order to reduce the level of EMI coupling as well as the length of the conductors of the lines.

The presentation describes a technical solution for 100 Mbit/s Ethernet Data transmission cabling. This solution considers the specific requirements of automotive wiring harness and manufacturing. It bases on standard automotive connectors and headers. Currently the development of automotive electronic architecture considers central ECU or data backbone structure for the upcoming EE architecture (e. g. single ECU for network; SEN). For these structures solid and cost effective data backbone solutions are essential. Ethernet, a wide distributed and well-known bus system for office and industry data distribution provide a wide range of software tools and many physical layer solutions. Several cabling systems are available. Based on this we propose a solution for automotive application.

In hybrid and electric vehicles, the control of the electric motor is a critical component of vehicle functions such as motoring, generating, engine-starting and braking. The efficient and accurate control of motor torque is performed by the motor controller. It is a complex system incorporating sensor sampling, data processing, controls, diagnostics, and 3-phase Pulse Width Modulation (PWM) generation which are executed in sub-100 uSec periods. Due to the fast execution rates, care must be taken in the software coding phase to ensure the algorithms will not exceed the target processor's throughput capability. Production motor control development often still follows the path of customer requirements, component requirements, simulation, hand-code, and verification test due to the concern for processor throughput. In the case of vehicle system controls, typically executed no faster than 5-10 mSec periods, auto-coding tools are used for algorithm development as well as testing.

As fuel prices continue to rise automotive manufacturers continue to push their suppliers to provide technology that improves the potential fuel efficiency of their applications. In addition there is an increasing trend towards smaller, lighter and more compact vehicles to mitigate the automotive carbon footprint. These movements necessitated the development of a new compact, low mass, variable displacement compressor to match the requirements for these smaller and more efficient vehicles. The new Delphi MVC, or Miniature Variable Compressor, meets these requirements by integrating the high efficiency of our latest swashplate variable compressor design into a compact and lightweight package. This design can be offered in a range of displacements from 80 to 100cc and can be offered as either internally or externally controlled to support the customer's needs.

The progressive trend towards the GDi engine downsizing, the focus on better fuel efficiency and performance, and the regulatory requirements with respect to the combustion emissions have brought the focus of attention on strategies for improvement of in-cylinder mixture preparation and identification and elimination of the sources of combustion emissions, in particular the in-cylinder particulate formation. This paper discusses the fuel system components, injector dynamics, spray characteristics and the single cylinder engine combustion investigation of a 40 [MPa] capable conventional GDi inwardly-opening multi-hole fuel injection system. It provides results of a study of the influence of fuel system pressure increase between 5 [MPa] to 40 [MPa], in conjunction with the injector static flow and spray pattern, on the combustion characteristics, specifically the particulate and gaseous emissions and the fuel economy.

The mean shift tracking algorithm has become a standard in the field of visual object tracking, caused by its real time capability and robustness to object changes in pose, size, or illumination. The standard mean shift tracking approach is an iterative procedure that is based on kernel weighted color histograms for object modelling and the Bhattacharyyan coefficient as a similarity measure between target and candidate histogram model. The benefits of the approach could not been transferred to monochrome vision systems yet, because the loss of information from color to grey-scale histogram object models is too high and the system performance drops seriously. We propose a new framework that solves this problem by using histograms of HoG-features as object model and the SOAMST approach by Ning et al. for track estimation. Mean shift tracking requires a histogram for object modelling.

The ultrasonic (US) welding of wires in automotive harnesses is increasingly used as an alternative to mechanical splices. However, this welding process may harm the electrical terminals crimped on the wires ends as a result on the energy propagation along the wire up the terminal with a frequency that is close to the terminals' natural frequencies. The modeling of the ultrasonic welding had been investigated by several authors from the process and weld strength perspective but the modeling of its effect on electrical terminals in automotive harnesses has not been given much attention in the literature. This paper describes and illustrates approaches used for modeling of the impact of the US welding on the electrical terminals in terms of stress and deformation from qualitative and quantitative perspectives and the related benefits/limitations from predictive standpoint. Illustrations are given on an actual terminal with respect to a typical ultrasonic welding process.

This study is concerned with quantitative analysis of the primary atomization, regarding the droplet size-velocity distribution function, of a multi-hole GDi plume through application of the Volume-of-Fluid Large Eddy Simulation (VOF-LES) method. The distinguishing feature of this study is the inclusion of an accurate seat /nozzle flow domain into the simulation. A VOF-LES study of the seat-nozzle flow and the near-field primary atomization of a single plume of a GDi multi-hole seat is performed. The geometry pertains to a purpose-built 3-hole GDi seat with three identical flow hole and counter-bore nozzles, arranged with 120° circumferential spacing. The VOF-LES prediction of the jet primary breakup structure and near-field macroscale is compared with spray imaging data. The droplet size and velocity distributions within a 4mm vicinity of the nozzle are analyzed. The results show production of a wide droplet size distribution through the jet primary atomization.

Innovative nozzle hole shapes for inwardly opening multi-hole gasoline direct injectors offer opportunities for improved mixture formation and particulate emissions reduction. Compared to increased fuel pressure, an alternative associated with higher system costs and increased pumping work, nozzle hole shaping simply requires changes to the injector nozzle shape and may have the potential to meet Euro 6 particulate regulations at today's 200 bar operating pressure. Using advanced laser drilling technology, injectors with non-round nozzle holes were built and tested on a single-cylinder engine with a centrally-mounted injector location. Particulate emissions were measured and coking deposits were imaged over time at several operating fuel pressures. This paper presents spray analysis and engine test results showing the potential benefits of alternative non-round nozzle holes in reducing particulate emissions and enhancing robustness to coking with various operating fuel pressures.

Development of in-cylinder spray targeting, plume penetration and atomization of the gasoline direct-injection (GDi) multi-hole injector is a critical component of combustion developments, especially in the context of the engine downsizing and turbo-charging trend that has been adopted in order to achieve the European target CO2, US CAFE, and concomitant stringent emissions standards. Significant R&D efforts are directed towards the optimization of injector nozzle designs in order to improve spray characteristics. Development of accurate predictive models is desired to understand the impact of nozzle design parameters as well as the underlying physical fluid dynamic mechanisms resulting in the injector spray characteristics. This publication reports Large Eddy Simulation (LES) analyses of GDi single-hole skew-angled nozzles, with β=30° skew (bend) angle and different nozzle geometries.

During the evolution of Hybrid vehicles as well as electrical vehicles the need for an additional Voltage level was defined for the utilization of high power loads like electrical compressors, electrical heaters as well as power steering and electrical pumps. The main systems benefit is the generation of approximately 12 kW electrical power by a traditional belt driven Generator. This allows boost function for acceleration and recuperation for mild hybrid vehicles with the target to reduce up to 15% CO2 by keeping the traditional thermal based engines. Delphi has developed systems and components that meet the special 48 Volt related electrical requirements on arcing, hot plugging and corrosion. Our benefit is the long term expertise within the total system know how and the derived technical specification and needs.

Variable displacement compressors have proven to be more energy efficient than the equivalent compressor with fixed displacement for mobile A/C applications. Variable displacement compressors de-stroke rather than cycle to prevent the evaporator from freezing. Cycling an internally controlled variable compressor is counter intuitive, yet results in a 15-20% reduction in the energy used by the compressor as demonstrated by tests on multiple vehicle applications. Externally controlled variable compressors have the highest energy efficiency and extending cycling to these compressors during cool temperatures reduces the compressor energy consumption by 10%.

In hybrid electric vehicles (HEVs) and full electric vehicles (EVs), efficient electrical power management with proper supply of power at the required voltage levels is essential. A DC (Direct Current)-DC converter is one of the key electrical units in a HEV/EV. The DC-DC converter dealt in the present work is intended to create the DC voltages necessary to power the accessories. The electronic circuit in this DC-DC converter consists of high power devices like Metal-Oxide Semiconductor Field-Effect Transistors (MOSFETs), inductors, transformers, etc. mounted on a printed circuit board (PCB). The DC-DC converter interacts with a high voltage battery pack and supplies a low voltage power to the accessory battery. Due to this power handling operation, the devices in the convertor experience high temperatures. The temperature rise of the devices beyond the permissible limits could be detrimental to an efficient and safe operation of the converter.

Advanced development engines are one-of-a-kind and expensive and generally have few, if any, spare parts available. These engines are particularly vulnerable to damage during control and calibration development due to unintended control actions from newly-generated algorithms, errant operator control commands, or lack of understanding of control limits for safe operation. Engine damage can result in significant program delays and expenses. Delphi is developing control systems and calibrations for the vehicle implementation of an experimental engine concept which incorporates a new high efficiency combustion process. Many of the algorithms within the control structure are new and untested, and therefore represent significant risk to these engines. The large amount of data displayed on computer test control screens makes human monitoring of all parameters nearly impossible, especially when display windows are layered on top of one another.

Delphi Diesel Systems' 2700bar Proven F2E Distributed Pump Common Rail System (DPCRS) has been developed to meet the requirements of Euro VI and future emissions legislation and is now in volume production in Heavy Duty Vehicles. Incorporating a number of ground breaking new technologies, the system offers numerous performance advantages. F2E provides full common rail functionality for camshaft driven Fuel Injection Equipment (FIE) engines with minimum modification. By delivering precise and accurate control of multiple injections at maximum rail pressure across all engine operating conditions, the system minimizes the demands on exhaust after treatment systems. Additionally F2E provides real time flexible capacity by employing a unique method of pump fuel metering, enabling the most efficient and accurate transient control of rail pressure combined with the low NVH and optimised efficiency.

Fuel systems associated with Gasoline Direct Injection (GDi) engines operate at pressures significantly higher than Port Fuel Injection (PFI) engine fuel systems. Because of these higher pressures, GDi fuel systems require a high pressure fuel pump in addition to the conventional fuel tank lift pump. Such pumps deliver fuel at high pressure to the injectors multiple times per engine cycle. With this extra hardware and repetitive pressurization events, vehicles equipped with GDi fuel systems typically emit higher levels of audible noise than those equipped with PFI fuel systems. A common technique employed to cope with pump noise is to cover or encase the pump in an acoustic insulator, however this method does not address the root causes of the noise. To contend with the consumer complaint of GDi system noise, Delphi and Magneti Marelli have jointly developed a high pressure fuel pump with reduced audible output by concentrating on sources of noise generation within the pump itself.

Most current automotive and light truck fuel level sensors are essentially rotary potentiometers that have been designed to survive the chemically harsh environments found in the fuel tank. This paper will chronicle the design improvements made from the early wire wound versions to today's more robust thick film ink systems. The paper will highlight potential failure modes and discuss techniques to reduce noise and increase wear life. Data will be provided regarding changes in the circuit layout, ink compositions, and contact materials. Special consideration will be given to the adverse effects associated with the reactive sulfur prevalent in today's fuels.